Design of a 75GHz Low Voltage-Continuous Wave Gyrotron with Mode Converter

The gyrotron is widely studied for its ability to generate high frequency and high power microwaves. When the operating voltage is lower, the volume of the power system and the water cooling system can be smaller, which makes the gyrotron more convenient for experimental research and industrial use. Therefore, a 10kV, 1A low-voltage continuous wave gyrotron is designed, including an electro-optical system, a high-frequency resonant cavity, and a mode converter TE01-TE 11 mode. The electron gun emits a current density of 600 mA/cm2, and the electron injection transversal and vertical velocity ratio is 1.52 velocity spread is 5%' and the output power of the design gyrotron is 1.5 kW with efficiency of 15%. Particle-in-cell simulation shows that and an operating frequency of 75.6 GHz. The mode converter adopts an axis perturbation method with a total length of 59.72 mm, a center frequency of 75.6 GHz, a single frequency point conversion efficiency of 99.8%, and a conversion efficiency of 90% or more with a bandwidth of 2.8 GHz.